BAE systems chief executive Sir Ian King told the Defence Select Committee in the Commons on Wednesday that the company had been asked to consider a number of options ranging from "one carrier to no carriers".

There are fears that any downgrading of the programme could cost thousands of jobs at shipyards on the Clyde and at Rosyth.

The figures were obtained by Thomas Docherty, Labour MP for Dunfermline and West Fife, and show that "equipment sub-contract" orders placed between November 2006 to June 2010 have been awarded to 68 different companies across 60 UK parliamentary constituencies. The figures were revealed in an answer from MP Peter Luff, Parliamentary under-secretary of state for defence, after a parliamentary question was submitted by Mr Docherty.

The new figures were released as Labour's team in Govan launched a petition, organised by MSP candidate Stephen Curran and Ian Davidson, Labour MP for Glasgow South West, calling on the Ministry Of Defence to end speculation around the carriers.

Mr Docherty, who represents the Rosyth dockyard, said: "These figures highlight that the carrier contracts don't just affect thousands of jobs here in Rosyth and on the Clyde or indeed just across Scotland, but in fact across the whole of the United Kingdom. To rip up these contracts worth millions at this stage would not only be financial madness, but political suicide and I hope the coalition Government sees sense."

Shadow Scottish Secretary Jim Murphy, also Labour MP for East Renfrewshire, said: "The carriers are built by proud men and women in proud yards. If the Tories sink the boats they'll sink the prospects of thousands of families across the UK but cancelling the carriers will cost more than human misery for the workforce.

"We'll lose the technical skills that are so vital for this country to have and they can't be replaced. Being able to build warships means we don't have to rely on other countries to do it for us."

He continued: "The carriers are vital for our Royal Navy that sails the seas, defending our interests across the world and protecting our shores at home. In an uncertain world, we need the flexibility the carriers offer to project our naval and military power around the world."